Since playing Kate for six seasons on “Lost,” Evangeline Lilly has become a virtual standard-bearer for midriff-exposing tomboys. But that’s also the reason you haven’t seen her in as many roles since: she has a few stipulations that characters must meet in order for her to consider playing them, including no tank tops, and perhaps even more crucially, no love triangles. But as a massive fan of J.R.R. Tolkien’s novels, Lilly thrilled at the chance to join the cast of Peter Jackson’s adaptations of “The Hobbit”—even if the character was completely original, and as she soon discovered, finds herself in a love triangle.

Feeling a bit under the weather during the Los Angeles press day for “The Hobbit: The Desolation of Smaug,” Lilly spoke to The Playlist via telephone as she scurried from one promotional event to the next. In addition to talking about her fan trepidations about having a new character added to Tolkien’s sacrosanct source material, Lilly discussed the challenges in bringing Tauriel to life, and finally, reflected on the opportunities, and deal-breakers, that guide her choices as an actress these days.

You’ve talked a lot about being a fan of Tolkien’s work. Specifically as a fan, what would you have hated most about someone creating a new character for “The Hobbit” before you learned what they were planning with Tauriel?As a fan, the thing that would have annoyed me most is if they would have done a pat, gratuitous romance and that was all there was to the character. That would have annoyed the hell out of me. So once they kind of described the character and explained her purpose, explained her role and explained her abilities and what a force of nature she would be, I was like, “Oh, okay, that’s in keeping with Tolkien.” I mean, Tolkien wasn’t much a romantic; he loved creating heroes, and he also loved creating a dichotomy between good and evil, and that is exactly what Tauriel does.

When you took on the character, what was the thing you knew was most important to satisfy you as a fan, personally, regardless of other fans’ reactions?I think the thing that I knew I had to…make the character distinct from the elves we’ve seen before, but in keeping with the elves that we saw in the “Lord of the Rings” trilogy. Because the elves in the “Lord of the Rings” trilogy not only embodied in my mind exactly what Tolkien described in his book—I thought they gave them a flawless perfection of elfhood—but also that has come to be accepted as the standard for a Tolkien elf. I think the fans fell in love with Galadriel and Arwen and they wouldn’t have wanted something that was too much of a departure from those two performances. So without copying those performances and going back to reference them—I had them in mind—I made sure Tauriel was in keeping with those two performances.

When you’re going back to do reshoots, how much ownership of this character can you take to create a cohesive portrayal of Tauriel, and how much do you just have to rely on Peter to do that once you’re done playing the role?You know, it was a real combination of both. I was fortunate in that I was the only actor on set who nobody would have had a preconceived notion about what she was about and who she was. So I got to be an active participant with Peter, Fran [Walsh] and Phil[ippa Boyens] in creating the character, and that was an incredibly rewarding experience for me. But at the end of the day, I’m still just an actor, and actors actually have very little control over the finished product, including themselves. There’s so much that goes on with editing, there’s so much that goes on with take choice, there’s so much that goes on with camera angles—not just editing a scene out, but sometimes scenes are made like patchwork quilts. They’ll take a piece of your performance from over here, and a piece from over there, and put them together. So ultimately it was in Peter’s hands, and that was a real reassurance to me, and one of the reasons I took the job. Because I knew I would trust him absolutely to make me look good.

What has been the most surprising thing to you in watching the character?This is going to sound so crazy to you because nobody sees it the way I see it, but I was actually surprised at how little action Tauriel saw (laughs). Because the amount of stunts and the amount of fights I actually did on set, what showed up in the film paled in comparison to what I put down. So that was sort of a surprise. But I was also surprised because I really wanted Tauriel to exude a certain kind of fresh innocence that you don’t see in Arwen or Galadriel, because they were much older, wiser elves. I wanted to somehow get it through to the audience through the performance that she was young and full of life, and I was surprised at how strongly that came through. I was pleased, but I was surprised, I just didn’t think when I watched back the takes, I didn’t think I was really getting that message across. And then I watched the film, and I was like, “Oh, there’s a certain kind of happy light to her,” which I’m so pleased, and I think that’s partly my performance and partly what Pete did with the performance and how he makes these beautiful little effects in post that sort of help enhance the performance.

Your character has this great, tender relationship with Aidan Turner’s character. How much time did you spend together on set, and then given the differences between them, what did you determine motivated the attraction between them? Do they share something we don’t yet know, or is it just a matter of you two being understandably very attracted to one another?(laughs) Well, first of all, to answer how much time I got to spend working alongside him, the answer is not enough. Aidan was a total delight to work with. He is a happy, passionate, generous guy, and generous actor and co-star, so I looked greatly forward to all of the scenes I had to play with him.

And then as far as the attraction between them or whatever is that sparkle or that chemistry that you can see, that I really believe is that they’re both extremely passionate beings. He is passionate about his people and his heritage and their legacy, and he has an exuberance for life. He’s a kind of slightly reckless, energetic, sparkly young dwarf, and she is a passionate elf. She is extremely passionate about justice, as the head of the Silvan guard, she’s passionate about her culture, and the forest and nature and her connection to it—and the innocence and the precious purity of nature and protecting it. And I think that, even in human beings, probably the most attractive thing in another person is passion, and I think passion can cross over racial divides—which is essentially what Tauriel and Kili are dealing with, a racial divide. I mean, it’s a species divide, but it’s the same idea—they have a prejudice against each other when they first meet, and very quickly I think their passions overtake that prejudice.

You mentioned that the only stipulation about taking the role of Tauriel was that you didn’t want to be in a love triangle. After having played Kate on “Lost” for six seasons, do you have any other things that you did not want to do again, or that might be deal-breakers when you’re looking at roles?Yeah, very much so. It would take a lot, it would take a pretty darn impressive project for me to play a kind of tank top-wearing, tomboy girl, woman. I don’t want to say I’m bored with that because that might be a bit too extreme, but I just feel like I have exhausted that part of my performing life, and I really enjoyed the feminine element of playing Tauriel, because it was such a departure from playing Kate. That’s not to say that I’m not looking for roles with strong women—I think that’s always what I’m looking for—but I think strength comes in all different shapes and sizes, and I’m interested mostly at this point finding roles where I can demonstrate the kind of strength that comes out of softness and vulnerability and passion and compassion. Because I actually think that’s a more distinctly female brand of strength that has often been associated with weakness, and I love the idea of debunking that myth—that being vulnerable and passionate makes you weak. I think it makes you infinitely stronger than somebody who is maybe violent and powerful.

Given the complexity that you brought to this character, what is the thing that you’re most looking forward to seeing brought to life in the final film?There’s a couple of things I’m most excited about seeing in the next film, but I would give away the plot if I said them. But one of them I’m very much looking forward to seeing is the final scenes in the Battle of the Five Armies, because when we shot those scenes, I really and truly gave it every ounce of everything I had. I was a puddle on the set floor when those scenes were finished, when that week of work was finished. I had nothing physically, mentally or emotionally left to give because I’d spent myself. So when you put that kind of effort into something, it’s hard to wait to see the end result—you want to see if it paid off. And that’s how I feel about the final scenes in the Battle of the Five Armies.